In digital imaging of microscopic image used in the filed such as pathological diagnosis, a sample (slide) on which a pathological tissue or the like is fixed is imaged by an imaging apparatus via a microscope. Here, an image of the range that needs to be observed by the microscope in the sample (hereinafter, observation target range) is generally captured a plurality of times while moving the visual filed range of the imaging apparatus because the visual field range of the imaging apparatus via the microscope is fine. The captured images (hereinafter, microscopic images) are brought into alignment with each other and bonded to each other, thereby generating a microscopic image in the observation target range.
In many cases, the entire sample is imaged at another magnification or by another optical system or another image sensor before microscopic imaging, and image processing is performed on the thus-obtained image (hereinafter, entire image), thereby detecting the above-mentioned observation target range. In Patent Document 1, for example, “specimen area detection method” in which the observation target range is detected from an image of the entire sample and the range is imaged via a microscope is disclosed.
The entire image is used also as a list image (thumbnail image) for an observer to search for a desired microscopic image. Furthermore, information (character, barcode, etc.) or the like for identifying the sample is displayed on the sample in some cases, and such information is read from the entire image.